A two-dimensional (2D) silicon-based image sensor is capable of capturing an image from light having wavelengths in the visible range. For certain applications, such as for gesture recognition, liveness detection and/or autofocusing, it would be desirable to be able to additionally capture depth information from the image scene.
One solution for capturing both a 2D image and depth information would be to provide a 2D image sensor and a separate depth sensor for capturing the depth information. However, such a solution has drawbacks in terms of cost, bulkiness, and also due to the difficulty in accurately aligning the depth information with the captured image when the fields of view of the sensors are not exactly identical.
A further solution could be to integrate the pixels of the depth sensor for capturing the depth information within the 2D image sensor. However, the technology used for implementing 2D image pixels and depth pixels is generally not the same, and thus the integration of these two types of pixels in a single array would lead to a complex and costly process. Furthermore, there are likely to be compatibility issues with topologies of the connections of these two types of sensors.
There is thus a need in the art for a compact solution providing a 2D image sensor and a depth sensor in a single device.